tcg: Introduce goto_ptr opcode and tcg_gen_lookup_and_goto_ptr
Instead of exporting goto_ptr directly to TCG frontends, export
tcg_gen_lookup_and_goto_ptr(), which calls goto_ptr with the pointer
returned by the lookup_tb_ptr() helper. This is the only use case
we have for goto_ptr and lookup_tb_ptr, so having this function is
very convenient. Furthermore, it trivially allows us to avoid calling
the lookup helper if goto_ptr is not implemented by the backend.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1493263764-18657-2-git-send-email-cota@braap.org>
Message-Id: <1493263764-18657-3-git-send-email-cota@braap.org>
Message-Id: <1493263764-18657-4-git-send-email-cota@braap.org>
Message-Id: <1493263764-18657-5-git-send-email-cota@braap.org>
[rth: Squashed 4 related commits.]
Signed-off-by: Richard Henderson <rth@twiddle.net>
diff --git a/tcg/README b/tcg/README
index a9858c2..bf49e82 100644
--- a/tcg/README
+++ b/tcg/README
@@ -477,6 +477,14 @@
instructions. Only indices 0 and 1 are valid and tcg_gen_goto_tb may be issued
at most once with each slot index per TB.
+* lookup_and_goto_ptr tb_addr
+
+Look up a TB address ('tb_addr') and jump to it if valid. If not valid,
+jump to the TCG epilogue to go back to the exec loop.
+
+This operation is optional. If the TCG backend does not implement the
+goto_ptr opcode, emitting this op is equivalent to emitting exit_tb(0).
+
* qemu_ld_i32/i64 t0, t1, flags, memidx
* qemu_st_i32/i64 t0, t1, flags, memidx
diff --git a/tcg/aarch64/tcg-target.h b/tcg/aarch64/tcg-target.h
index 1a5ea23..b82eac4 100644
--- a/tcg/aarch64/tcg-target.h
+++ b/tcg/aarch64/tcg-target.h
@@ -77,6 +77,7 @@
#define TCG_TARGET_HAS_mulsh_i32 0
#define TCG_TARGET_HAS_extrl_i64_i32 0
#define TCG_TARGET_HAS_extrh_i64_i32 0
+#define TCG_TARGET_HAS_goto_ptr 0
#define TCG_TARGET_HAS_div_i64 1
#define TCG_TARGET_HAS_rem_i64 1
diff --git a/tcg/arm/tcg-target.h b/tcg/arm/tcg-target.h
index 75ea247..c114df7 100644
--- a/tcg/arm/tcg-target.h
+++ b/tcg/arm/tcg-target.h
@@ -123,6 +123,7 @@
#define TCG_TARGET_HAS_mulsh_i32 0
#define TCG_TARGET_HAS_div_i32 use_idiv_instructions
#define TCG_TARGET_HAS_rem_i32 0
+#define TCG_TARGET_HAS_goto_ptr 0
enum {
TCG_AREG0 = TCG_REG_R6,
diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h
index 4275787..59d9835 100644
--- a/tcg/i386/tcg-target.h
+++ b/tcg/i386/tcg-target.h
@@ -107,6 +107,7 @@
#define TCG_TARGET_HAS_muls2_i32 1
#define TCG_TARGET_HAS_muluh_i32 0
#define TCG_TARGET_HAS_mulsh_i32 0
+#define TCG_TARGET_HAS_goto_ptr 0
#if TCG_TARGET_REG_BITS == 64
#define TCG_TARGET_HAS_extrl_i64_i32 0
diff --git a/tcg/ia64/tcg-target.h b/tcg/ia64/tcg-target.h
index 42aea03..901bb75 100644
--- a/tcg/ia64/tcg-target.h
+++ b/tcg/ia64/tcg-target.h
@@ -173,6 +173,7 @@
#define TCG_TARGET_HAS_mulsh_i64 0
#define TCG_TARGET_HAS_extrl_i64_i32 0
#define TCG_TARGET_HAS_extrh_i64_i32 0
+#define TCG_TARGET_HAS_goto_ptr 0
#define TCG_TARGET_deposit_i32_valid(ofs, len) ((len) <= 16)
#define TCG_TARGET_deposit_i64_valid(ofs, len) ((len) <= 16)
diff --git a/tcg/mips/tcg-target.h b/tcg/mips/tcg-target.h
index f46d64a..e3240cf 100644
--- a/tcg/mips/tcg-target.h
+++ b/tcg/mips/tcg-target.h
@@ -130,6 +130,7 @@
#define TCG_TARGET_HAS_muluh_i32 1
#define TCG_TARGET_HAS_mulsh_i32 1
#define TCG_TARGET_HAS_bswap32_i32 1
+#define TCG_TARGET_HAS_goto_ptr 0
#if TCG_TARGET_REG_BITS == 64
#define TCG_TARGET_HAS_add2_i32 0
diff --git a/tcg/ppc/tcg-target.h b/tcg/ppc/tcg-target.h
index abd8b3d..a9aa974 100644
--- a/tcg/ppc/tcg-target.h
+++ b/tcg/ppc/tcg-target.h
@@ -82,6 +82,7 @@
#define TCG_TARGET_HAS_muls2_i32 0
#define TCG_TARGET_HAS_muluh_i32 1
#define TCG_TARGET_HAS_mulsh_i32 1
+#define TCG_TARGET_HAS_goto_ptr 0
#if TCG_TARGET_REG_BITS == 64
#define TCG_TARGET_HAS_add2_i32 0
diff --git a/tcg/s390/tcg-target.h b/tcg/s390/tcg-target.h
index cbdd2a6..6b7bcfb 100644
--- a/tcg/s390/tcg-target.h
+++ b/tcg/s390/tcg-target.h
@@ -92,6 +92,7 @@
#define TCG_TARGET_HAS_mulsh_i32 0
#define TCG_TARGET_HAS_extrl_i64_i32 0
#define TCG_TARGET_HAS_extrh_i64_i32 0
+#define TCG_TARGET_HAS_goto_ptr 0
#define TCG_TARGET_HAS_div2_i64 1
#define TCG_TARGET_HAS_rot_i64 1
diff --git a/tcg/sparc/tcg-target.h b/tcg/sparc/tcg-target.h
index b8b74f9..9348ddd 100644
--- a/tcg/sparc/tcg-target.h
+++ b/tcg/sparc/tcg-target.h
@@ -123,6 +123,7 @@
#define TCG_TARGET_HAS_muls2_i32 1
#define TCG_TARGET_HAS_muluh_i32 0
#define TCG_TARGET_HAS_mulsh_i32 0
+#define TCG_TARGET_HAS_goto_ptr 0
#define TCG_TARGET_HAS_extrl_i64_i32 1
#define TCG_TARGET_HAS_extrh_i64_i32 1
diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
index 6b1f415..87f673e 100644
--- a/tcg/tcg-op.c
+++ b/tcg/tcg-op.c
@@ -2587,6 +2587,18 @@
tcg_gen_op1i(INDEX_op_goto_tb, idx);
}
+void tcg_gen_lookup_and_goto_ptr(TCGv addr)
+{
+ if (TCG_TARGET_HAS_goto_ptr && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
+ TCGv_ptr ptr = tcg_temp_new_ptr();
+ gen_helper_lookup_tb_ptr(ptr, tcg_ctx.tcg_env, addr);
+ tcg_gen_op1i(INDEX_op_goto_ptr, GET_TCGV_PTR(ptr));
+ tcg_temp_free_ptr(ptr);
+ } else {
+ tcg_gen_exit_tb(0);
+ }
+}
+
static inline TCGMemOp tcg_canonicalize_memop(TCGMemOp op, bool is64, bool st)
{
/* Trigger the asserts within as early as possible. */
diff --git a/tcg/tcg-op.h b/tcg/tcg-op.h
index c68e300..5d3278f 100644
--- a/tcg/tcg-op.h
+++ b/tcg/tcg-op.h
@@ -796,6 +796,17 @@
*/
void tcg_gen_goto_tb(unsigned idx);
+/**
+ * tcg_gen_lookup_and_goto_ptr() - look up a TB and jump to it if valid
+ * @addr: Guest address of the target TB
+ *
+ * If the TB is not valid, jump to the epilogue.
+ *
+ * This operation is optional. If the TCG backend does not implement goto_ptr,
+ * this op is equivalent to calling tcg_gen_exit_tb() with 0 as the argument.
+ */
+void tcg_gen_lookup_and_goto_ptr(TCGv addr);
+
#if TARGET_LONG_BITS == 32
#define tcg_temp_new() tcg_temp_new_i32()
#define tcg_global_reg_new tcg_global_reg_new_i32
diff --git a/tcg/tcg-opc.h b/tcg/tcg-opc.h
index f06f894..956fb1e 100644
--- a/tcg/tcg-opc.h
+++ b/tcg/tcg-opc.h
@@ -193,6 +193,7 @@
TCG_OPF_NOT_PRESENT)
DEF(exit_tb, 0, 0, 1, TCG_OPF_BB_END)
DEF(goto_tb, 0, 0, 1, TCG_OPF_BB_END)
+DEF(goto_ptr, 0, 1, 0, TCG_OPF_BB_END | IMPL(TCG_TARGET_HAS_goto_ptr))
DEF(qemu_ld_i32, 1, TLADDR_ARGS, 1,
TCG_OPF_CALL_CLOBBER | TCG_OPF_SIDE_EFFECTS)
diff --git a/tcg/tcg-runtime.h b/tcg/tcg-runtime.h
index 114ea6f..c41d38a 100644
--- a/tcg/tcg-runtime.h
+++ b/tcg/tcg-runtime.h
@@ -24,6 +24,8 @@
DEF_HELPER_FLAGS_1(ctpop_i32, TCG_CALL_NO_RWG_SE, i32, i32)
DEF_HELPER_FLAGS_1(ctpop_i64, TCG_CALL_NO_RWG_SE, i64, i64)
+DEF_HELPER_FLAGS_2(lookup_tb_ptr, TCG_CALL_NO_WG_SE, ptr, env, tl)
+
DEF_HELPER_FLAGS_1(exit_atomic, TCG_CALL_NO_WG, noreturn, env)
#ifdef CONFIG_SOFTMMU
diff --git a/tcg/tcg.c b/tcg/tcg.c
index cb898f1..564292f 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -424,6 +424,11 @@
qemu_log_unlock();
}
#endif
+
+ /* Assert that goto_ptr is implemented completely. */
+ if (TCG_TARGET_HAS_goto_ptr) {
+ tcg_debug_assert(s->code_gen_epilogue != NULL);
+ }
}
void tcg_func_start(TCGContext *s)
diff --git a/tcg/tcg.h b/tcg/tcg.h
index 6c216bb..5ec48d1 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -699,6 +699,7 @@
extension that allows arithmetic on void*. */
int code_gen_max_blocks;
void *code_gen_prologue;
+ void *code_gen_epilogue;
void *code_gen_buffer;
size_t code_gen_buffer_size;
void *code_gen_ptr;
diff --git a/tcg/tci/tcg-target.h b/tcg/tci/tcg-target.h
index 838bf3a..0696328 100644
--- a/tcg/tci/tcg-target.h
+++ b/tcg/tci/tcg-target.h
@@ -85,6 +85,7 @@
#define TCG_TARGET_HAS_muls2_i32 0
#define TCG_TARGET_HAS_muluh_i32 0
#define TCG_TARGET_HAS_mulsh_i32 0
+#define TCG_TARGET_HAS_goto_ptr 0
#if TCG_TARGET_REG_BITS == 64
#define TCG_TARGET_HAS_extrl_i64_i32 0
